Vasquez-Bonilla Aldo A, Yáñez-Sepúlveda Rodrigo, Monsalves-Álvarez Matías, Tuesta Marcelo, Duclos-Bastías Daniel, Cortés-Roco Guillermo, Olivares-Arancibia Jorge, Guzmán-Muñoz Eduardo, López-Gil José Francisco
Faculty of Sport Sciences, University of Extremadura, 10001 Caceres, Spain.
Faculty Education and Social Sciences, Universidad Andres Bello, Viña del Mar 2520000, Chile.
J Funct Morphol Kinesiol. 2025 Apr 17;10(2):136. doi: 10.3390/jfmk10020136.
This study aimed to evaluate the reliability of muscle oxygen saturation (SmO) and its correlation with variables from an inertial measurement unit (IMU) sensor placed on the knee at different exercise intensities. Fourteen university athletes participated in the study. Incremental ergospirometry was performed to exhaustion to calculate V'Omax, determine training zones, heart rate, and workload using the IMU, and analyze muscle metabolism by SmO. The analysis revealed significant differences between moderate-to-high-intensity zones (80-89% vs. 50-69%, Δ = 27% of SmO; < 0.001) and high-intensity zones (90-100% vs. 50-79%, Δ = 35% of SmO; < 0.001). SmO values showed moderate reliability at moderate exercise intensities (e.g., ICC 0.744 at 50%) and high variability at higher intensities, with ICC values around 0.577-0.594, and CV% increasing up to 77.7% at 100% intensity, indicating decreasing consistency as exercise intensity increases. SmO significantly decreases with increasing angular velocity (β = -13.9, < 0.001), while knee joint load only shows significant correlations with SmO in the moderate-to-high-intensity zones (r = 0.569, = 0.004) and high-intensity zones (r = 0.455, = 0.012). SmO is a key predictor of performance during maximal incremental exercise, particularly in high-intensity zones. Moreover, SmO has the potential to serve as a physiological marker of the internal load on the muscles surrounding the knee during exercise. The SmO decrease could depend on the angular velocity and impact of the exposed knee during running.
本研究旨在评估肌肉氧饱和度（SmO）的可靠性及其与放置在膝盖上的惯性测量单元（IMU）传感器在不同运动强度下的变量之间的相关性。14名大学运动员参与了该研究。进行递增运动心肺功能测试直至力竭，以计算最大摄氧量（V'Omax）、确定训练区域、心率，并使用IMU确定工作量，同时通过SmO分析肌肉代谢。分析显示，中高强度区域（80 - 89% 对比 50 - 69%，SmO的变化量Δ = 27%；P < 0.001）和高强度区域（90 - 100% 对比 50 - 79%，SmO的变化量Δ = 35%；P < 0.001）之间存在显著差异。SmO值在中等运动强度下显示出中等可靠性（例如，在50%强度时组内相关系数ICC为0.744），而在较高强度下具有较高变异性，ICC值约为0.577 - 0.594，在100%强度时变异系数CV%高达77.7%，表明随着运动强度增加一致性降低。SmO随角速度增加而显著降低（β = -13.9，P < 0.001），而膝关节负荷仅在中高强度区域（r = 0.569，P = 0.004）和高强度区域（r = 0.455，P = 0.012）与SmO显示出显著相关性。SmO是最大递增运动期间运动表现的关键预测指标，尤其是在高强度区域。此外，SmO有可能作为运动期间膝盖周围肌肉内部负荷的生理标志物。SmO的降低可能取决于跑步过程中暴露膝盖的角速度和冲击力。
